Android应用程序中Activity的生命周期

对于Android来说Activity的生命周期是非常的重要，尤其是对于新学者来说，只有充分了解了Activity的生命周期，才能写出优良用户体验的应用

下面来看看具体的Activity生命周期

图1是官方给我们提供的Activity生命周期图：

图1

大家大概了解了Activity的生命周期后，请看下面的代码

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Log.i("MY_LOG", "---onCreate");
	}
	
	@Override
	protected void onStart() {
		// TODO Auto-generated method stub
		super.onStart();
		Log.i("MY_LOG", "---onStart");
	}
	
	@Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onRestoreInstanceState(savedInstanceState);
		Log.i("MY_LOG", "---onRestoreInstanceState");
	}
	
	@Override
	protected void onRestart() {
		// TODO Auto-generated method stub
		super.onRestart();
		Log.i("MY_LOG", "---onRestart");
	}
	
	@Override
	protected void onSaveInstanceState(Bundle outState) {
		// TODO Auto-generated method stub
		super.onSaveInstanceState(outState);
		Log.i("MY_LOG", "---onSaveInstanceState");
	}
	
	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		Log.i("MY_LOG", "---onResume");
	}
	
	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		Log.i("MY_LOG", "---onPause");
	}
	
	@Override
	protected void onStop() {
		// TODO Auto-generated method stub
		super.onStop();
		Log.i("MY_LOG", "---onStop");
	}
	
	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		Log.i("MY_LOG", "---onDestroy");
	}

}

此段代码列出了Activity的各个生命周期所要执行的方法，现在对这些方进行验证。

当第一次启动应用程序时，打印出的LOG如下图：